In this chapter, we will understand the factors of comparison between STLC and SDLC. Let us consider the following points and thereby, compare STLC and SDLC.

  • STLC is part of SDLC. It can be said that STLC is a subset of the SDLC set.

  • STLC is limited to the testing phase where quality of software or product ensures. SDLC has vast and vital role in complete development of a software or product.

  • However, STLC is a very important phase of SDLC and the final product or the software cannot be released without passing through the STLC process.

  • STLC is also a part of the post-release/ update cycle, the maintenance phase of SDLC where known defects get fixed or a new functionality is added to the software.

The following table lists down the factors of comparison between SDLC and STLC based on their phases −

Requirement Gathering
  • Business Analyst gathers requirements.
  • Development team analyzes the requirements.
  • After high level, the development team starts analyzing from the architecture and the design perspective.
  • Testing team reviews and analyzes the SRD document.
  • Identifies the testing requirements - Scope, Verification and Validation key points.
  • Reviews the requirements for logical and functional relationship among various modules. This helps in the identification of gaps at an early stage.
  • The architecture of SDLC helps you develop a high-level and low-level design of the software based on the requirements.
  • Business Analyst works on the mocker of UI design.
  • Once the design is completed, it is signed off by the stakeholders.
  • In STLC, either the Test Architect or a Test Lead usually plan the test strategy.
  • Identifies the testing points.
  • Resource allocation and timelines are finalized here.
  • Development team starts developing the software.
  • Integrate with different systems.
  • Once all integration is done, a ready to test software or product is provided.
  • Testing team writes the test scenarios to validate the quality of the product.
  • Detailed test cases are written for all modules along with expected behaviour.
  • The prerequisites and the entry and exit criteria of a test module are identified here.
Environment Set up
  • Development team sets up a test environment with developed product to validate.
  • The Test team confirms the environment set up based on the prerequisites.
  • Performs smoke testing to make sure the environment is stable for the product to be tested.
  • The actual testing is carried out in this phase. It includes unit testing, integration testing, system testing, defect retesting, regression testing, etc.
  • The Development team fixes the bug reported, if any and sends it back to the tester for retesting.
  • UAT testing performs here after getting sign off from SIT testing.
  • System Integration testing starts based on the test cases.
  • Defects reported, if any, get retested and fixed.
  • Regression testing is performed here and the product is signed off once it meets the exit criteria.
Deployment/ Product Release
  • Once sign-off is received from various testing team, application is deployed in prod environment for real end users.
  • Smoke and sanity testing in production environment is completed here as soon as product is deployed.
  • Test reports and matrix preparation are done by testing team to analyze the product.
  • It covers the post deployment supports, enhancement and updates, if any.
  • In this phase, the maintaining of test cases, regression suits and automation scripts take place based on the enhancement and updates.